Free calculator
Paving Slab Calculator
Work out a slab minimum and a separate order quantity using the slab dimensions and your chosen wastage allowance.
Open calculator →Garden project hub
Paving & patios
A patio is not one quantity: slab count, waste, sub-base and bedding should remain separate.
Use the right quantity tool
Calculators for paving & patios
Move from patio area to slabs, a separate wastage allowance and the layers beneath the paving.
Free calculator
Patio Materials Calculator
Estimate paving, compacted sub-base, bedding and optional simple jointing quantities for a patio build-up.
Open calculator →Free calculator
Garden Area Calculator
Measure lawns, beds and awkward garden shapes in square metres before moving into a material or planting calculator.
Open calculator →Free calculator
Garden Edging Calculator
Calculate linear edging for beds, circles, paths, gaps and multiple runs, then convert to pieces or rolls.
Open calculator →Before you order
Keep the project decisions separate from the arithmetic
How many slabs?
Use the slab calculator when the question is the paving unit count. Enter the actual slab dimensions and keep the mathematical minimum separate from the chosen ordering allowance.
What goes underneath?
Use Patio Materials Calculator when the question expands to compacted sub-base and bedding volume. Those layers use area × depth and may need supplier-specific density or order factors.
Wastage is a decision, not a hidden constant
Cuts, curves, patterns, breakage and batch-matching can alter the extra quantity. The guide explains the trade-off; the calculator keeps the percentage editable.
Supporting guidance
Read the guide when the difficult part is choosing the input
Practical guide
Paving Wastage Guide
Choose an ordering allowance for cuts, breakage, curves and patterns instead of assuming every patio needs the same percentage.
Read guide →Continue the project
Useful next routes
Move to the next quantity only when it describes a genuinely different part of the job.
Landscaping materialsSee gravel, membrane, edging and sleepers alongside paving.Choose a paving allowanceUnderstand when a simple layout and a complex pattern justify different ordering approaches.Layer depth referenceCheck the arithmetic behind sub-base and bedding volumes.Measure the patio footprintGet the square metres before counting slabs.